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25312. Water stress and abscisic acid treatments induce the CAM pathway in the epiphytic fern Vittaria lineata (L.) Smith

Creator:
Minardi, B. D., Voytena, A. P. L., Santos, M., and Randi, Á. M.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, pigmenty, photosynthesis, pigments, Brazílie, Brasil, chlorophyll fluorescence, malate, morphoanatomy, photosynthetic pathway, Vittaria lineata, 2, and 581
Language:
Multiple languages
Description:
Among various epiphytic ferns found in the Brazilian Atlantic Forest, we studied Vittaria lineata (L.) Smith (Polypodiopsida, Pteridaceae). Anatomical characterization of the leaf was carried out by light microscopy, fluorescence microscopy, and scanning electron microscopy. V. lineata possesses succulent leaves with two longitudinal furrows on the abaxial surface. We observed abundant stomata inside the furrows, glandular trichomes, paraphises, and sporangia. We examined malate concentrations in leaves, relative water content (RWC), photosynthetic pigments, and chlorophyll (Chl) a fluorescence in control, water-deficient, and abscisic acid (ABA)-treated plants. Plants subjected to drought stress (DS) and treated by exogenous ABA showed significant increase in the malate concentration, demonstrating nocturnal acidification. These findings suggest that V. lineata could change its mode of carbon fixation from C3 to the CAM pathway in response to drought. No significant changes in RWC were observed among treatments. Moreover, although plants subjected to stress treatments showed a significant decline in the contents of Chl a and b, the concentrations of carotenoids were stable. Photosynthetic parameters obtained from rapid light curves showed a significant decrease after DS and ABA treatments., B. D. Minardi, A. P. L. Voytena, M. Santos, Á. M. Randi., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

25313. Water-deficiency effects on single leaf gas exchange and on C4 pathway enzymes of maize genotypes with differing abiotic stress tolerance

Creator:
Sicher, Richard, Bunce, J., Barnaby, J., and Bailey, B.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, sucha, kukuřice, photosynthesis, C4 photosynthesis, drought, enzyme activities, gene expression, phosphoenolpyruvate carboxylase, maize, abiotic stress, 2, and 581
Language:
Multiple languages
Description:
Responses to drought were studied using two maize inbred lines (B76 and B106) and a commercial maize hybrid (Zea mays L. cv. Silver Queen) with differing resistance to abiotic stress. Maize seedlings were grown in pots in controlled environment chambers for 17 days and watering was withheld from one half the plants for an additional 11 days. On the final treatment date, leaf water potentials did not differ among genotypes and were -0.84 and -1.49 MPa in the water sufficient and insufficient treatments, respectively. Greater rates of CO2 assimilation were retained by the stress tolerant maize inbred line, B76, in comparison to the other two genotypes 11 days after watering was withheld. Rates of CO2 assimilation for all three genotypes were unaffected by decreasing the measurement O2 concentration from 21 to 2% (v/v). Activities of phosphoenolpyruvate carboxylase (PEPC), NADP-malic enzyme (NADP-ME), and NADP malate dehydrogenase were inhibited from 25 to 49% by the water deficiency treatment. Genotypic differences also were detected for the activities of NADP-ME and for PEPC. Changes of transcript abundance for the three C4 pathway enzymes also varied among watering treatments and genotypes. However, examples where transcripts decreased due to drought were associated with the two stress susceptible genotypes. The above results showed that enzymes in the C4 photosynthetic pathway were less inhibited by drought in stress tolerant compared to stress susceptible maize genotypes., R. Sicher, J. Bunce, J. Barnaby, B. Bailey., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

25314. Wavelet decomposition in the earth's gravity field investigation

Creator:
Bogusz, Janusz, Klos, Anna, and Kosek, Wieslaw
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, gravitace, zemětřesení, gravity, earthquake, GGP, wavelet decomposition, Earth’s gravity field changes, 7, and 551
Language:
English
Description:
This paper presents the results of the application of wavelet decomposition to processing data from the GGP sites (The Global Geodynamics Project). The GGP is an international project within which the Earth's gravity field changes are recorded with high accuracy at a number of stations worldwide using superconducting gravimeters. Data with a 5-second sampling interval from Wettzell and Bad Homburg were used for the research. The wavelet transform enables the investigation of the temporal changes of the oscillation amplitudes or the decomposition of the time series for the analysis of the required frequencies. The wavelet decomposition was performed using the regular orthogonal symmetric Meyer wavelet. The research concerned data from an earthquake period recorded at various locations and a quiet period when the gravimeters worked without any disturbances. The decomposition was followed by the Fast Fourier Transform for signal frequency components and then by correlation analyses of corresponding frequency components (for periods from 10 to 60 000 seconds) for all sensor combinations, for the quiet and the earthquake periods separately. Frequency components defining long term changes for all sensor combinations, as well as combinations between two sensors at the same site for the quiet days are characterised by high correlation coefficients. For the time of the earthquake, the Wettzell site data proved strong correlation for all frequency components, while the Bad Homburg site data showed an unexpected decrease of correlation for the majority of frequency components. The authors also showed that wavelet decomposition can be a good method of data interpolation, especially from the time of earthquakes. Moreover, it is a very useful tool for filtering the data and removing the noises., Janusz Bogusz, Anna Klos and Wieslaw Kosek., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

25315. Weak- and strong-type inequality for the cone-like maximal operator in variable Lebesgue spaces

Creator:
Szarvas, Kristóf and Weisz, Ferenc
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
matematika, Lebesgueovy prostory, nerovnosti (matematika), mathematics, Lebesgue spaces, inequalities (mathematics), variable Lebesgue space maximal operator γ-rectangle Besicovitch’s covering theorem weak-type inequality strong-type inequality, maximal operator, γ-rectangle, Besicovitch’s covering theorem, weak-type inequality, strong-type inequality, 13, and 51
Language:
English
Description:
The classical Hardy-Littlewood maximal operator is bounded not only on the classical Lebesgue spaces Lp(Rd) (in the case p > 1), but (in the case when 1/p(·) is log-Hölder continuous and p- = inf{p(x): x\in Rd > 1) on the variable Lebesgue spaces Lp(·)(Rd), too. Furthermore, the classical Hardy-Littlewood maximal operator is of weak-type (1, 1). In the present note we generalize Besicovitch’s covering theorem for the so-called γ-rectangles. We introduce a general maximal operator Msγδ, and with the help of generalized Φ-functions, the strong- and weak-type inequalities will be proved for this maximal operator. Namely, if the exponent function 1/p(·) is log-Hölder continuous and p- ≥ s, where 1 ≤ s ≤ ∞ is arbitrary (or p- ≥ s), then the maximal operator Msγδ is bounded on the space Lp(·)(Rd) (or the maximal operator is of weak-type (p(·), p(·)))., Kristóf Szarvas, Ferenc Weisz., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

25316. Weather-dependent fluctuations in the abundance of the oak processionary moth, Thaumetopoea processionea (Lepidoptera: Notodontidae)

Creator:
Csóka, György, Hirka, Anikó, Szöcs, Levente, Móricz, Norbert, Rasztovits, Ervin, and Pödör, Zoltán
Format:
print, počítač, and online zdroj
Type:
model:article and TEXT
Subject:
motýli, dolování dat, butterflies, data mining, Lepidoptera, Notodontidae, Thaumetopoea processionea, light trap, population fluctuation, Moran-effect, drought, oak defoliator, CReMIT-analysis, 2, and 59
Language:
English
Description:
Population fluctuations of the well-known oak defoliator, the oak processionary moth (Thaumetopoea processionea L.), were studied using light trap data and basic meteorological parameters (monthly average temperatures, and precipitation) at three locations in Western Hungary over a period of 15 years (1988-2012). The fluctuations in the numbers caught by the three traps were strongly synchronized. One possible explanation for this synchrony may be similar weather at the three trapping locations. Cyclic Reverse Moving Interval Techniques (CReMIT) were used to define the period of time in a year that most strongly influences the catches. For this period, we defined a species specific aridity index for Thaumetopoea processionea (THAU-index). This index explains 54.8-68.9% of the variation in the yearly catches, which indicates that aridity, particularly in the May-July period was the major determinant of population fluctuations. Our results predict an increasing future risk of Oak Processionary Moth (OPM) outbreaks and further spread if the frequency of severe spring/summer droughts increases with global warming., György Csóka, Anikó Hirka, Levente Szöcs, Norbert Móricz, Ervin Rasztovits, Zoltán Pödör., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

25317. Weathering by dolomite dissolution reponsible for the formation of an important palaeotological locality in the Prague Synform

Creator:
Rowberry, Matt, Dubois, Caroline, Kaufmann, Olivier, Baele, Jean-Marc, and Jan Blahůt
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
spodní devon, vápenec, lower devon, limestones, Slivenec (Praha, Česko), Prague (Czechia), Slivenec (Prague, Czechia), carbonate rock weathering index, polarising light microscopy, cathodoluminescence microscopy, calcite dissolution, dolomite dissolution, Prague Synform, 7, and 551
Language:
English
Description:
Karst landforms can result from a single stage process in which chemical dissolution and mechanical erosion proceed simultaneously or from a two stage process in which chemical dissolution precedes mechanical erosion. During the second of these processes, chemical dissolution leads to the creation of karst features hosting a residual weathering product, here referred to as alterite. An example of one such feature is the enclosed mass of altered rock at Červený Quarry near Klukovice which represents one of the richest localities for exceptionally preserved echinoderm ossicles in the Prague Synform. In this study the processes responsible for the formation of this feature have been investigated. Nineteen samples were obtained from the bioclastic Slivenec Limestone and from these it has been possible to calculate the carbonate volume content, which defines the weathering intensity, and the carbonate rock weathering index, which defines the weathering state. The results demonstrate that carbonate dissolution has not been accompanied by gravitational compaction or the incorporation of mineral inputs. Thin sections analysed under polarised light and under cathodoluminescence emphasise heterogeneous dolomitisation of the limestone. As the weathering grade intensifies, empty rhomboidal pores become increasingly common until, ultimately, the rhomboidal forms are lost due to corrosion and enlargement. In contrast it is rare to find evidence of calcite dissolution and, therefore, the altered mass still hosts almost all of its post dolomitisation micrite, sparite, and bioclasts. Negligible calcite dissolution helps to explain the exceptional nature of the fossil preservation at the site while the dolomite dissolution accounts for the ease with which it is possible to extract the fossils. Further research should focus on better understanding the role of dolomite dissolution in the formation of other important palaeontological localities in the Prague Synform., Matt Rowberry, Caroline Dubois, Olivier Kaufmann, Jean-Marc Baele and Jan Blahůt., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

25318. Webové okénko

Creator:
Voháňka, Stanislav
Format:
print, text, and regular print
Type:
model:article, article, Text, and TEXT
Subject:
internet, tělo lidské, and lidé
Language:
Czech
Description:
Anatomický atlas Healtline Networks -- Visible Body Blog -- Interaktivní atlas lidské anatomie -- Atlas svalů -- Svalová anatomie pro EMG -- Anatomický atlas jehlové EMG and prim. MUDr. Stanislav Voháňka, CSc.,Mba
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

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